Genesis chief wholesale officer Tracey Hickman said the hydroelectric Waikaremoana Power Scheme, which generates 138MW of power, was the only major source of electricity generation for Hawke’s Bay and the East Coast for weeks after Cyclone Gabrielle. Photo / Warren Buckland
Genesis chief wholesale officer Tracey Hickman said the hydroelectric Waikaremoana Power Scheme, which generates 138MW of power, was the only major source of electricity generation for Hawke’s Bay and the East Coast for weeks after Cyclone Gabrielle. Photo / Warren Buckland
The hydroelectric Waikaremoana Power Scheme was the only major source of power generation in Hawke’s Bay for weeks after Cyclone Gabrielle devastated the region.
Reporter James Pocock takes a look inside to see how the three power stations, the first built almost a century ago, work.
Landslips from anearthquake about 2000 years ago formed the stunning Lake Waikaremoana.
Almost 100 years ago engineers looked at it and decided its dramatic nature could be harnessed.
The result in 2024 is a seven-turbine operation which now generates 138 megawatts of power using the force of water through up to seven turbines.
First completed in 1929, the Tuai power station was the first of three to make up the Waikaremoana Power Scheme, with Piripaua and Kaitawa coming later in 1943 and 1948 respectively.
Tuai carries three 20MW turbines, Piripaua has two 21MW turbines and Kaitawa has two 18MW turbines.
Water is transported to these stations through modified lakes, canals, dams and siphon systems which alter the natural pathway of the Waikaretaheke River catchment.
From Waikaremoana, the water flows into the Kaitawa power station which discharges water down a short canal and into Lake Kaitawa for use in the other two stations downstream.
Water discharged from turbines at Tuai power station goes into Lake Whakamarino where an intake for Piripaua power station is. Water from Piripaua is discharged into the natural Waikaretaheke riverbed via a tailrace.
Genesis chief wholesale officer Tracey Hickman said Waikaremoana was the only major source of electricity generation for Hawke’s Bay and the East Coast for weeks after Cyclone Gabrielle.
Built in 1948, Kaitawa Power at the Waikaremoana Power Scheme has two 18MW turbines. Photo / Warren Buckland
Gareth Gray, Genesis renewable energy control centre manager and principal hydrologist, said Genesis has a contract with Transpower so Genesis’ local staff can do maintenance on their behalf if Transpower cannot reach their infrastructure.
“The roads and bridges washed out between Napier and Gisborne and they were very thankful we were able to keep the lights on as the only generation on the east coast,” Gray said.
Seven of the 11 Genesis staff working at the Waikaremoana Power Scheme are locals from nearby Tuai.
Gray said the average daily inflow of water into Lake Waikaremoana during Cyclone Gabrielle peaked at 434 metres per second (cumecs). Genesis could only release about 40 to 50 cumecs at any time.
The average daily flow of water into Lake Waikaremoana during Cyclone Gabrielle peaked at 434 metres per second, with spikes up to 700 cumecs. Genesis could only release about 40 to 50 metres per second at any time. Photo / Warren Buckland
“You want to get the lake down as quickly as possible without causing downstream damage to the power scheme and the people downstream.”
Despite that, Gray said the scheme held up very well during the cyclone.
“We didn’t have anything washed away or undercut and the turbines kept going, the ones that were available.”
Ross Macdonald, Genesis site manager for the Waikaremoana Power Scheme, inside the Kaitawa power station. All three power stations are replacing their turbines which have reached the end of their 50-year lifespans. Photo / Warren Buckland
Ross Macdonald, Genesis site manager for the Waikaremoana Power Scheme, said the power that goes to Wairoa, Gisborne and up the East Cape has to come through Waikaremoana.
The turbines are going through the replacement process for the first time in Macdonald’s decades-long career as they reach the end of their lifecycles, typically 50 years long.
A Genesis worker checks lake conditions at Onepotu intake on Lake Waikaremoana which supplies water to the Kaitawa hydro power station through tunnels. Photo / Warren Buckland
When asked if there were any plans to expand operations at Waikaremoana, Hickman said Genesis was focused on preserving its existing renewable operations and was investing in solar and wind to meet decarbonisation goals, citing dry winters as a challenge for hydropower.
James Pocock joined Hawke’s Bay Today in 2021 and writes breaking news and features, with a focus on environment, local government and post-cyclone issues in the region. He has a keen interest in finding the bigger picture in research and making it more accessible to audiences. He lives in Napier. james.pocock@nzme.co.nz
